OK,
I found WHAT is causing this , but not a solution .
so SIMPLE schedules - are working fine .
Then i'm adding one COMPLEX to be run every hour a 5 minutes
Then i'm adding another COMPLEX to be run at several different minutes like :
localhost complex 5,20,35,50 --all-- --all-- --all-- --all--
and after that - cron is not adding or modifying anything untill ALL COMPLEX rules are deleted !
So please check the logic here (I'll only use SIMPLE for now, however i vitaly need variations for minutes in cron )